Civil Engineering Reference
In-Depth Information
flow has been solved for pipeline in the range of approximate equations. These ap-
proximate equations have been solved by numerical solutions of the nonlinear Navier-
Stokes equations in
Method of Characteristics (MOC).
1.2 mAteriAls And metHods
The pilot subject in our study was: “Interpenetration of two fluids at parallel between
plates and turbulent moving in pipe.” For data collection process, Rasht city water
main pipeline have been selected as Field Tests Model. Rasht city in the north of
Iran was located in Guilan province (1,050,000 population). Data have been collected
from the PLC of Rasht city water treatment plant. The pipeline was included water
treatment plant pump station (in the start of water transmission line), 3.595 km of
2*1200 mm diameter pre-stressed pipes and one 50,000 m³ reservoir (at the end of
water transmission line). All of these parts have been tied into existing water networks.
Long-distance water transmission lines must be economical, reliable, and expandable.
Therefore, present chapter shows safe hydraulic input to a network. This idea provides
wide optimization and risk-reduction strategy for Rasht city main pipeline. Records
were included multi-booster pressurized lines with surge protection ranging from
check valves to gas vessels (one-way surge tank). This chapter has particular pros-
pects for designing pressurized and pipeline segments. This means that by reduction
of unaccounted for water (UFW), energy costs can be reduced. Experiences have been
ensured reliable water transmission to the Rasht city main pipeline.
The MOC approach transforms the water hammer partial differential equations
into the ordinary differential equations along the characteristic lines defined as the
continuity equation and the momentum equation are needed to determine V and P
in a one-dimensional flow system. Solving these two equations produces a theoreti-
cal result that usually corresponds quite closely to actual system measurements if the
data and assumptions used to build the numerical model are valid. Transient analysis
results that are not comparable with actual system measurements are generally caused
by inappropriate system data (especially boundary conditions) and inappropriate as-
sumptions. The MOC is based on a finite difference technique where pressures are
computed along the pipe for each time step [14].
æ
(
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C gV
/
-
V
++
H
H
÷
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Le
ri
Le
ri
÷
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H
=
1/ 2
÷
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(1)
÷
P
ç
)
(
)
(
÷
-
Cgf
/
D
t DV
/2
V
-
VV
÷
ç
è
ø
Le
Le
ri
ri
æ
ö
(
) ( )(
)
V
++
V
gc H
/
-
H
ç
÷
Le
ri
Le
ri
÷
ç
V
=
1/ 2
,
÷
ç
(2)
÷
)
(
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P
ç
(
÷
ç
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-
f
D
t DV
/2
V
+
VV
÷
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Le
Le
ri
ri
Where
f=friction, C=slope (deg.), V=velocity, t=time, H=head (m).
1.2.1 regression equations
There is a relation between two or many
Physical Units of variables. For example,
there is a relation between volume of gases and their internal temperatures. The main
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